The present invention pertains to a liquid crystal electro-optical deflector.
To achieve angular scanning by laser beams of opto-electronic systems such as lidars, the general practice is to use devices such as galvanometrical mirrors, holographic disks or acousto-optical deflectors. All these components are difficult to apply and they require high control power.
For the mechanical devices, the scanning speed is limited to about 1.degree./ms for a beam section with a diameter of 1 cm. The high inertia of the mirrors even further limits the random access time.
With acousto-optical deflectors (LiNbO.sub.3, GaP, etc.), the major drawback is their very dissymmetrical pupil having typical dimensions of 100 .mu.m.times.10 mm, which requires the use of cylindrical optical coupling devices. Furthermore, the beam undergoes an often troublesome frequency shift that is a function of the angle of deflection. The small angles (of less than 1.degree.), the inadequate transmission as well as the sensitivity to polarization are all so many limits on the systems.